[The following is an exact transcript of this podcast.]

One of the goals of regenerative medicine is to make tissue to replace our own damaged body parts. That’s still a ways off. But starting with mouse embryonic stem cells, researchers have succeeded in creating heart muscle that actually beats. The study appears in the October 16th issue of the journal Science.

Different sets of progenitor cells in the heart give rise to two different types of heart cells—muscle and nonmuscle. To make beating heart muscle, researchers needed to figure out just which cells were the ones that they needed. They used colored fluorescent tags to identify the groups in question in embryos, allowing the correct cells to be harvested.

But that’s just step one. The cells needed to link up in a form that will allow them to beat together. So the researchers borrowed from microchip technology. They created patterns on a film, much like the design for a computer chip. Laying down the cells within these patterns forces them to take the distinctive shape of cardiac muscle cells, which lets the cells link and beat in sync. The ultimate goal is to grow beating heart muscle from a patient’s own cells. And thereby literally mend a broken heart.

—Cynthia Graber